A variety of tetra-micron-carboxylatodirhodium(II) and tetra-micron-carboxylatodirhodium(II,III) complexes will be synthesized and screened for anticancer activity using Ehrlich ascites, P388 and Sarcoma 180 ascites tumors. These compounds are known to be potent inhibitors of enzymes which contain sulfhydryl groups near or at the active site. We plan to determine the nature of the reactions and the product formed when rhodium(II) complexes react with compounds containing sulfhydryl groups. Mechanism of action studies will also be carried out using both the rhodium(II) and rhodium(II,III) complexes. BIBLIOGRAPHIC REFERENCES: R.A. Howard, T.G. Spring and J.L. Bear, The Interaction of Tetra-micron-Carboxylato-dirhodium (II) Complexes with Enzymes, Journal of Clinical Hematology and Anocology, The Third International Symposium on Platinum Coordination Complexes in Cancer Chemotherapy, 7, 391-400 (1977). K. Das, E.L. Simmons and J.L. Bear, The Thermodynamics and Kinetics of some Tetra-micron-Carboxylatodirhodium(II) Adduct Formation Reactions, Inorganic Chemistry 16, 1268 (1977).